The contents of 12 elements along with seven elemental ratios have been used to assign more than 900 heroin samples to the Golden Triangle or the Golden Crescent by a procedure which is faster than analysing their organic compounds. This new procedure was developed by scientists in China who were looking for a quicker alternative to existing methods which are based on the analysis of organic components, by-products and solvents.

Writing in Forensic Science International, Yao Liu and colleagues described how they used inductively coupled plasma mass spectrometry (ICPMS) to measure the abundances of 19 elements in 417 authenticated heroin samples. These originated from the Gold Triangle, which covers the mountainous region of Laos, Thailand and Myanmar or the Golden Crescent which straddles the mountains of Iran, Afghanistan and Pakistan.

When the results were subjected to statistical analysis, it was found that some elements and elemental ratios were good differentiators of the two sources of heroin. High levels of Cu, Pb and Zn and of the ratios Cd/V, V/Cr, Cd/Mn and Co/Ni were characteristic of heroin from the Golden Triangle, whereas high levels Ni, Cr, V, P, As, U and Se and the ratios Ba/Pb, P/V and U/Ba characterised the Golden Crescent heroin.

These criteria were applied to 907 further samples that had been seized in 2010-2012 in China ranging in purity from 5-83%. The results were generally consistent with those obtained by alkaloid profiling and impurity analysis but the ICPMS method is quicker and suitable for high-throughput screening.

The elemental differences are a result of a combination of factors such as the poppy growing environment, harvesting processes and the conversion of morphine to heroin.